The present disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides for fluid isolating pressure equalization in subterranean wells.
Various methods have been used to provide for pressure equalization in well tools. Such pressure equalization may be desirable, for example, to prevent excessive stress due to pressure differentials across walls of the well tools.
Devices such as bellows, membranes, floating pistons, etc. have been used in the past to provide for pressure equalization. However, each of these has disadvantages. Floating pistons are notorious for sticking and require dynamic seals, which may leak. Bellows are expensive to manufacture, and typically have extensive lengths of welds, which are prone to leakage. Membranes are inherently weak and prone to fatigue failure.
Therefore, it will be appreciated that advancements are needed in the art of pressure equalization in subterranean wells.